I've got an old JD book and it states in it that they (meaning Deere) has had a rotor combine testing in the field since the 1940s. It was that they never came up with a rotor combine that they thought was suitable enough until the STS. I was at a dealer combine clinic on the STSs before I even thought about one, and the rep from Deere that was on the STS project said that the best design for shelling corn they had did All of the separation right on the CORN HEAD! Can you imagine. He said it was great, but they never got the beans to work on a platform. Also said they had many better corn combines, but never got them to perform in beans. Now they have an awesome bean combine!